This invention generally relates to attachment of high strength polymeric members to a metallic member and particularly to the attachment of polymeric tubes to metallic tubes in intravascular devices such as catheters for use in percutaneous transluminal coronary angioplasty (PCTA).
In a typical PTCA procedure a dilatation balloon catheter is advanced over a guidewire to a desired location within the patient's coronary anatomy where the balloon of the dilatation catheter is properly positioned within the stenosis to be dilated. The balloon is then inflated to a predetermined size with radiopaque liquid at relatively high pressures (generally 4-20 atmospheres) to dilate the stenosed region of the diseased artery. One or more inflations may be needed to effectively dilate the stenosis. The catheter may then be withdrawn from the stenosis or advanced further into the patient's coronary anatomy to dilate additional stenoses.
The inflation pressures used in PTCA procedures have increased considerably due to the utilization of high strength balloon materials. However, such higher pressures also place substantial stress on other catheter components and particularly the junctions between various catheter components. Examples of such components and junctions are the adapter and the junction with the proximal end of a metallic hypotube and the adapter and the distal end of a metallic hypotube and the polymeric tubular products which form the distal portion of a rapid exchange type dilatation catheter. Present manufacturing procedures involve the use of adhesives, heat shrinking and the like which limit the materials which can be used and the combination of materials which can be used and which complicate the manufacturing procedure. What has been needed and has heretofore been unavailable is an uncomplicated procedure which produces high strength, hermetically sealed bonds.